N Engl J Med 2021 02 24;384(7):619-629. Epub 2020 Nov 24.
From the Clinical Pharmacology Section (V.A.S., P.S., M.V.B., N.S.), Intermediate Care Unit (M.G.V., C.V., H.G.M.), and Infectious Diseases Section (M.L.S.), Department of Internal Medicine, and the Departments of Research (V.A.S., D.H.G., L.G.P., W.H.B.) and Transfusional Medicine (L.D.B.P., D.M.S., P.J.C., S.A.), Hospital Italiano de Buenos Aires, Buenos Aires; Department of Virology, Leloir Institute Foundation, Buenos Aires (A.V.G., D.S.O.), the Departments of Transfusional Medicine (K.R.), Infectious Diseases, Sanatorio Agote (G.P.V.), and Critical Care, Clínica Zabala (E.A.M.), Swiss Medical, Buenos Aires, the Departments of Infection Control (W.C.) and Transfusional Medicine (O.A.T.), Hospital Universitario Austral, Pilar, the Departments of Internal Medicine (F.M.R.) and Transfusional Medicine (M.S.), Clínica Santa Isabel, Buenos Aires, the Departments of Emergency and Internal Medicine (L.D.B.P., G.F.) and Transfusional Medicine (W.E.S.), Hospital Italiano Agustín Rocca, San Justo, the Departments of Medicine (M.H.L.) and Transfusional Medicine (I.F.), Hospital General de Agudos José María Ramos Mejía, Buenos Aires, the Departments of Internal Medicine (P.E.P.) and Transfusional Medicine (E.R.), Sanatorio Trinidad de Palermo, Buenos Aires, the Departments of Clinical Research (N.A.F., M.E.) and Transfusional Medicine (G.A.S.), Hospital Privado de la Comunidad de Mar del Plata and Escuela Superior de Medicina Universidad Nacional de Mar del Plata, Mar del Plata (N.A.F., M.E.), the Departments of Internal Medicine (P.R.) and Transfusional Medicine (J.P.), Hospital Zonal Ramón Carrillo, Bariloche, and the Departments of Infectious Diseases (E.C.N.) and Transfusional Medicine (A.M.), Sanatorio Británico de Rosario, Santa Fé - all in Argentina; and the Biostatistics Research Branch (D.F.), Division of Clinical Research (D.F., H.C.L.), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD.
Background: Convalescent plasma is frequently administered to patients with Covid-19 and has been reported, largely on the basis of observational data, to improve clinical outcomes. Minimal data are available from adequately powered randomized, controlled trials.
Methods: We randomly assigned hospitalized adult patients with severe Covid-19 pneumonia in a 2:1 ratio to receive convalescent plasma or placebo. The primary outcome was the patient's clinical status 30 days after the intervention, as measured on a six-point ordinal scale ranging from total recovery to death.
Results: A total of 228 patients were assigned to receive convalescent plasma and 105 to receive placebo. The median time from the onset of symptoms to enrollment in the trial was 8 days (interquartile range, 5 to 10), and hypoxemia was the most frequent severity criterion for enrollment. The infused convalescent plasma had a median titer of 1:3200 of total SARS-CoV-2 antibodies (interquartile range, 1:800 to 1:3200). No patients were lost to follow-up. At day 30 day, no significant difference was noted between the convalescent plasma group and the placebo group in the distribution of clinical outcomes according to the ordinal scale (odds ratio, 0.83; 95% confidence interval [CI], 0.52 to 1.35; P = 0.46). Overall mortality was 10.96% in the convalescent plasma group and 11.43% in the placebo group, for a risk difference of -0.46 percentage points (95% CI, -7.8 to 6.8). Total SARS-CoV-2 antibody titers tended to be higher in the convalescent plasma group at day 2 after the intervention. Adverse events and serious adverse events were similar in the two groups.
Conclusions: No significant differences were observed in clinical status or overall mortality between patients treated with convalescent plasma and those who received placebo. (PlasmAr ClinicalTrials.gov number, NCT04383535.).